From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751848AbdLBNzZ (ORCPT ); Sat, 2 Dec 2017 08:55:25 -0500 Received: from merlin.infradead.org ([205.233.59.134]:50372 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751756AbdLBNzY (ORCPT ); Sat, 2 Dec 2017 08:55:24 -0500 Date: Sat, 2 Dec 2017 14:55:02 +0100 From: Peter Zijlstra To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com Subject: Re: [PATCH tip/core/rcu 10/10] rcu: Account for rcu_all_qs() in cond_resched() Message-ID: <20171202135502.GV3326@worktop> References: <20171201192122.GA19301@linux.vnet.ibm.com> <1512156104-20104-10-git-send-email-paulmck@linux.vnet.ibm.com> <20171202085626.GS3326@worktop> <20171202122220.GM7829@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171202122220.GM7829@linux.vnet.ibm.com> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Dec 02, 2017 at 04:22:20AM -0800, Paul E. McKenney wrote: > Because there are a few key places within RCU and rcutorture that need it. > Without it, there are scenarios where the new cond_resched() never gets > activated, and thus doesn't take effect. Ah, I missed that interaction. > The key point is that with this series in place, it should not be necessary > to use cond_resched_rcu_qs() outside of kernel/rcu and kernel/torture.c. > Which is a valuable step forward, right? Quite.